His past taught him to never mix duty with desire. Her lifetime on the run left her yearning for stability. As danger closes in from all sides, their greatest vulnerability becomes each other. —GRIT— I thought I buried my heart alongside the woman I failed to protect. Now, as K19 Sentinel Cyber’s lead field operative, I keep things professional—no exceptions. Until I’m assigned to work with a woman who’s spent her life hiding from organized crime families. When we go undercover as a married couple to infiltrate a dangerous operation, I tell myself it’s just another mission. But there’s nothing pretend about how Lumi makes me feel. Every touch, every glance during training sessions ignites something I thought was dead. As threats mount and secrets surface, I’m torn between duty and the woman who’s crashed through my defenses. I’ve sworn to protect her with my life, but I never expected she might end up saving mine. —LUMI— I joined K19 Sentinel Cyber to stop running and start fighting back against the criminals who controlled my existence. What I didn’t expect was Grit—intense, overprotective, and impossible to ignore. He thinks I need to be shielded, but he has no idea what I’m capable of. When our undercover operation reveals shocking connections between my past and our mission, everything I thought I knew unravels. Suddenly, I’m not just hunting dangerous men—I’m discovering truths about myself and the father I never knew. As bullets fly and loyalties shift, Grit becomes my anchor in the storm. But in our world, letting someone in is the greatest risk I've ever taken—and potentially the most rewarding.